1975～2009年锡林郭勒盟生态系统宏观格局及其动态变化

基于MSS、TM、ETM+以及HJ-1等遥感影像,构建内蒙古锡林郭勒盟1975~2009年长时间序列生态系统宏观结数据库,分析区域生态系统空间分布格局、动态变化及驱动机制。研究表明:①草地生态系统是锡林郭勒盟主体生态系统,草地占全区总面积比例始终在86%以上。②锡林郭勒盟生态系统演变过程明显以2000年为界:2000年前草地生态系统持续、加速萎缩,荒漠、农田等生态系统不断扩张;2000年后草地生态系统萎缩迅速得到遏制和逆转,农田和荒漠等生态系统扩张趋势也得到遏制。③区域气候变化及人类土地利用活动对生态系统演变有显著加速和减速作用。

The Ecosystem Distribution and Dynamics in Xilingol League in 1975-2009

Xilingol League,located in the south-east edge of Inner Mongolia Plateau,is one of the typical ecological fragile zones belonging to the Chinese Northern Farming-Pastoral Belt.Based on the remote sensing images including the MSS,TM/ETM+ data from 1975 to 2005 and the latest HJ-1A/B CCD data in 2009,also supported by the computer aided artificially visual interpreting method,a large scale,long temporal sequences database was firstly rebuilt about the regional macro ecosystem structure and their dynamics in the region of Xilingol.Furthermore,based on the spatial-temporal information platform,the spatial pattern of regional ecosystem,the evolution characteristics and their driving mechanism were then analyzed.The results show that: 1) From the east to the west in Xilingol,the ecosystem pattern appears as "forest-meadow steppe-typical steppe-desert steppe-steppelike desert";and from the south to the north,it appears as "agriculture-farming-pastoral-animal husbandry".Grassland ecosystem is always the dominant type in Xilingol,while the temperate grassland with medium coverage is the majority sub-type.2) The ecosystem has been changed much since 1975s.The transformation process is divided obviously in the year of 2000.Before 2000,at the cost of continuous and accelerated extraction of grassland ecosystem,the desert,farmland,and forest ecosystem experienced a sustained and enhanced expansion process.After 2000,the tendency of grassland shrinking stopped and then revered,while the expansion trends of farmland and desert ecosystem then also turned down and back-spin.3) The spatial pattern of ecosystem is mainly controlled by the regional tectonic,pale climate change,and human migration and land development activities.In the backgrounds of climate change since 1950s,those major land use policies have remarkable acceleration or deceleration role on the regional ecological system evolution process.